El acompañamiento pedagógico como estrategia de formación docente en servicio: reflexiones para el contexto peruano

En acuerdo con el equipo de la Dirección de Formación Docente en Servicio (DIFODS) del Ministerio de Educación (MINEDU), este documento es un primer aporte para la construcción del referente teórico institucional que permite sustentar la apuesta ministerial por el acompañamiento pedagógico como principal estrategia formativa. El documento ha permitido alinear enfoques, sustentarlos a la luz de la literatura internacional e identificar también algunos puntos que requerirían de mayor definición por parte de los equipos responsables de las estrategias de acompañamiento pedagógico en el MINEDU

El acompañamiento pedagógico como estrategia de formación docente en servicio: reflexiones para el contexto peruano

En acuerdo con el equipo de la Dirección de Formación Docente en Servicio (DIFODS) del Ministerio de Educación (MINEDU), este documento es un primer aporte para la construcción del referente teórico institucional que permite sustentar la apuesta ministerial por el acompañamiento pedagógico como principal estrategia formativa. El documento ha permitido alinear enfoques, sustentarlos a la luz de la literatura internacional e identificar también algunos puntos que requerirían de mayor definición por parte de los equipos responsables de las estrategias de acompañamiento pedagógico en el MINEDU

Topological Progression in Proliferating Epithelia Is Driven by a Unique Variation in Polygon Distribution

Morphogenesis is consequence of lots of small coordinated variations that occur during development. In proliferating stages, tissue growth is coupled to changes in shape and organization. A number of studies have analyzed the topological properties of proliferating epithelia using the Drosophila wing disc as a model. These works are based in the existence of a fixed distribution of these epithelial cells according to their number of sides. Cell division, cell rearrangements or a combination of both mechanisms have been proposed to be responsible for this polygonal assembling. Here, we have used different system biology methods to compare images from two close proliferative stages that present high morphological similarity. This approach enables us to search for traces of epithelial organization. First, we show that geometrical and network characteristics of individual cells are mainly dependent on their number of sides. Second, we find a significant divergence between the distribution of polygons in epithelia from mid-third instar larva versus early prepupa. We show that this alteration propagates into changes in epithelial organization. Remarkably, only the variation in polygon distribution driven by morphogenesis leads to progression in epithelial organization. In addition, we identify the relevant features that characterize these rearrangements. Our results reveal signs of epithelial homogenization during the growing phase, before the planar cell polarity pathway leads to the hexagonal packing of the epithelium during pupal stages.LME is supported by the Miguel Servet (Instituto Carlos III) program that also funded the work. LME and DSG are funded by the Spanish Ministry of Science (BFU2011-25734). AS is funded by the Consejería de Innovación, Ciencia y Empresa of the Junta de Andalucía.Peer Reviewe

Topological Progression in Proliferating Epithelia Is Driven by a Unique Variation in Polygon Distribution

Morphogenesis is consequence of lots of small coordinated variations that occur during development. In proliferating stages, tissue growth is coupled to changes in shape and organization. A number of studies have analyzed the topological properties of proliferating epithelia using the Drosophila wing disc as a model. These works are based in the existence of a fixed distribution of these epithelial cells according to their number of sides. Cell division, cell rearrangements or a combination of both mechanisms have been proposed to be responsible for this polygonal assembling. Here, we have used different system biology methods to compare images from two close proliferative stages that present high morphological similarity. This approach enables us to search for traces of epithelial organization. First, we show that geometrical and network characteristics of individual cells are mainly dependent on their number of sides. Second, we find a significant divergence between the distribution of polygons in epithelia from mid-third instar larva versus early prepupa. We show that this alteration propagates into changes in epithelial organization. Remarkably, only the variation in polygon distribution driven by morphogenesis leads to progression in epithelial organization. In addition, we identify the relevant features that characterize these rearrangements. Our results reveal signs of epithelial homogenization during the growing phase, before the planar cell polarity pathway leads to the hexagonal packing of the epithelium during pupal stages.España, Ministero de Ciencia BFU2011-2573

Rules of tissue packing involving different cell types: human muscle organization

Natural packed tissues are assembled as tessellations of polygonal cells. These include skeletal muscles and epithelial sheets. Skeletal muscles appear as a mosaic composed of two different types of cells: the “slow” and “fast” fibres. Their relative distribution is important for the muscle function but little is known about how the fibre arrangement is established and maintained. In this work we capture the organizational pattern in two different healthy muscles: biceps brachii and quadriceps. Here we show that the biceps brachii muscle presents a particular arrangement, based on the different sizes of slow and fast fibres. By contrast, in the quadriceps muscle an unbiased distribution exists. Our results indicate that the relative size of each cellular type imposes an intrinsic organization into natural tessellations. These findings establish a new framework for the analysis of any packed tissue where two or more cell types exist.España, Gobierno BFU2011-2573

Identifying the most suitable endogenous control for determining gene expression in hearts from organ donors

<p>Abstract</p> <p>Background</p> <p>Quantitative real-time reverse transcription PCR (qRT-PCR) is a useful tool for assessing gene expression in different tissues, but the choice of adequate controls is critical to normalise the results, thereby avoiding differences and maximizing sensitivity and accuracy. So far, many genes have been used as a single reference gene, without having previously verified their value as controls. This practice can lead to incorrect conclusions and recent evidence indicates a need to use the geometric mean of data from several control genes. Here, we identified an appropriate set of genes to be used as an endogenous reference for quantifying gene expression in human heart tissue.</p> <p>Results</p> <p>Our findings indicate that out of ten commonly used reference genes (<it>GADPH, PPIA, ACTB, YWHAZ, RRN18S, B2M, UBC, TBP, RPLP and HPRT</it>), <it>PPIA</it>, <it>RPLP </it>and <it>GADPH </it>show the most stable gene transcription levels in left ventricle specimens obtained from organ donors, as assessed using geNorm and Normfinder software. The expression of <it>TBP </it>was found to be highly regulated.</p> <p>Conclusion</p> <p>We propose the use of <it>PPIA</it>, <it>RPLP </it>and <it>GADPH </it>as reference genes for the accurate normalisation of qRT-PCR performed on heart tissue. <it>TBP </it>should not be used as a control in this type of tissue.</p

Neuromuscular disease classification system

Diagnosis of neuromuscular diseases is based on subjective visual assessment of biopsies from patients by the pathologist specialist. A system for objective analysis and classification of muscular dystrophies and neurogenic atrophies through muscle biopsy images of fluorescence microscopy is presented. The procedure starts with an accurate segmentation of the muscle fibers using mathematical morphology and a watershed transform. A feature extraction step is carried out in two parts: 24 features that pathologists take into account to diagnose the diseases and 58 structural features that the human eye cannot see, based on the assumption that the biopsy is considered as a graph, where the nodes are represented by each fiber, and two nodes are connected if two fibers are adjacent. A feature selection using sequential forward selection and sequential backward selection methods, a classification using a Fuzzy ARTMAP neural network, and a study of grading the severity are performed on these two sets of features. A database consisting of 91 images was used: 71 images for the training step and 20 as the test. A classification error of 0% was obtained. It is concluded that the addition of features undetectable by the human visual inspection improves the categorization of atrophic pattern